Apparatus for controlling the flow of articles

ABSTRACT

An apparatus for controlling the flow of articles includes an infeed conveyor and an outfeed conveyor spaced apart from the infeed conveyor to define a space therebetween. A movable transport member is disposed across and movable along the space. Transport member includes a rotatable member drivingly engaged by the infeed and outfeed conveyors so as to rotate as either of the infeed and outfeed conveyors move. The transport member travels along the space if a relative speed difference exists between the infeed and outfeed conveyors. An article transfer member is carried by the transport member and is disposed between the infeed and outfeed conveyors to transfer articles between the conveyors as the rotatable member rotates.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for controlling the flowof articles from an upstream delivery station to a downstream receivingstation; and more particularly to an apparatus wherein articles can beaccumulated between an upstream delivery station and a downstreamreceiving station, and fed to the downstream receiving station in afirst in first out (FIFO) sequence.

Heretofore, accumulators have been utilized between an upstream deliverystation and a downstream receiving station to accumulate articles whenthe capacity of the downstream receiving station is either shut down orrun at a speed wherein it cannot handle the number of articles being fedby the upstream delivery station. One particular accumulator isdisclosed in U.S. Pat. No. 4,018,325. One problem with such accumulatorsis that the last article fed into the accumulator is the first articlefed out of the accumulator and, as a result, it is difficult to keeptrack of the batch from which a particular article came from, and thesequence in which the articles are fed from the upstream deliverystation.

Attempts have been made to produce accumulators wherein the first in isthe first out article as disclosed in U.S. Pat. No. 4,513,858.

The present invention is particularly adapted for use wherein anupstream delivery station may be a filling station for placing contentsinto a package and feeding them to a downstream receiving stationwherein the package is placed in boxes. It of course can be used in manydifferent industries wherein there is a need to control the rate of flowof articles between an upstream delivery station and a downstreamreceiving station.

SUMMARY OF THE INVENTION

One of the objects of the present invention is to provide an apparatusfor controlling the flow of articles from an upstream delivery stationto a downstream receiving station and for temporarily storing thearticles there between and feeding the first article stored therein outfirst (FIFO) in a controlled flow to minimize damage from pressure orwear not only inside, but on entry and at next machine.

Another important object of the present invention is to provide anapparatus for accumulating articles wherein there is a minimum ofcontact between the articles in the accumulator. This minimizes damageto labels and printed material carried on the outside of the article orpackage or to the article itself.

Still another important object of the present invention is to provide anarticle storage accumulator which permits a large number of articles tobe stored in a relatively small amount of floor space, thus reducing thedistance between an upstream delivery station and a downstream receivingstation.

Still another object of the present invention is to provide anaccumulator which operates automatically responsive to the requirementsof a downstream receiving station to store articles temporarily prior todelivering the articles to the downstream receiving station in a firstin first out (FIFO) sequence.

It is another object of the present invention to decrease the potentialfor damage or breakage as well as jamming or wedging of items to beaccumulated because of the manner in which the articles are stored on amoving conveyor.

It is another important object of the present invention to provide aneffective and reliable accumulator which can be readily modified foraccumulating articles of different sizes and configurations.

Still another important object of the present invention is to provide anapparatus for accumulating articles in a vertically stacked arrangementon a moving conveyor system constructed in the form of a verticallyextending spiral.

Still another important object of the present invention is to provide anaccumulator wherein articles are temporarily stored on a moving conveyorwhich permits the loading and unloading of the moving conveyorresponsive to the capacity of a downstream receiving station.

Another important object of the present invention is to provide anaccumulator which utilizes an infeed and outfeed conveyor fortemporarily storing articles at a rate depending on the relative speedof travel of the infeed conveyor and the outfeed conveyor.

Another object of the present invention is to provide an effective andreliable apparatus for controlling the flow of articles from an upstreamdelivery station to an downstream receiving station at a relatively highspeed.

Another object also is to make a more responsive apparatus therebyminimizing the need for additional conveyors.

The above objects are accomplished by an apparatus that controls theflow of articles being transported on a main conveyor from an upstreamdelivery station to a downstream receiving station according to thecapacity of the downstream receiving station. The apparatus includes anendless infeed conveyor and endless outfeed conveyor. A supportstructure supports the infeed conveyor and the outfeed conveyor where asubstantial portion of the run of the conveyors are parallel to eachother providing a space therebetween. A track is carried by the supportstructure. The track extends along the parallel run of the infeed andoutfeed conveyors. A transport member is carried by the track in thespace provided between the infeed and outfeed conveyors for movementalong the length of the infeed and outfeed conveyors.

An infeed drive mechanism drives the infeed conveyor in one direction,and an outfeed drive mechanism drives the outfeed conveyor in a seconddirection. A deflective plate or any other suitable mechanism is usedfor transferring the articles from a main conveyor onto the infeedconveyor. A rotatable member is carried by the transport member. Thereis a driving coupling provided between the infeed conveyor and therotatable member through which the infeed conveyor rotates the rotatablemember. There is also a driving coupling provided between the rotatablemember and the outfeed conveyor for rotating the rotatable member andcausing the transport member to move along the guide track in adirection depending upon the relative speed of travel of the infeed andoutfeed conveyors. An article transfer member is carried by thetransport member for transferring articles from the infeed conveyor to aposition along the outfeed conveyor as the transport member moves alongthe guide track.

The accomplishment of the objects discussed above will become readilyapparent from the following description of various embodiments of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating an apparatus for controlling the flowof articles in its basic forms.

FIG. 2 is a plan view of the apparatus of FIG. 1 showing articles beingloaded into the apparatus.

FIG. 3 is a plan view of a modified form of the invention.

FIG. 4 is a schematic diagram illustrating an apparatus storing articlesin a vertical spiral.

FIG. 5 is a plan view, partially in section, illustrating infeed andoutfeed conveyors as well as a transport member forming part of theinvention.

FIG. 6 is a plan view illustrating the transport member going around acurved portion of the track.

FIG. 7 is a plan view illustrating a linkage mechanism for controllingthe movement of the wheels of the transport member.

FIG. 8 is a cross-sectional view illustrating a track for supporting theoutfeed conveyor and an article being transported thereon.

FIG. 9 is a sectional view taken along line 9—9 of FIG. 8 illustrating arotatable member forming part of a transport member and drivers carriedon the conveyors.

FIG. 10 is a schematic diagram illustrating the manner in which thetransport member is moved between an infeed and outfeed conveyor.

FIG. 11 is an exploded view of a transport member.

FIG. 12 is a cross-sectional view of the transfer member.

FIG. 13 is a schematic representation of a modified form of thetransport member.

FIG. 14 is a perspective view illustrating a modified form of the drivemechanism for the transport member.

FIG. 15 is a plan view illustrating in schematic form a modified form ofa deflecting member (drive position) used with the transport member.

FIG. 16 is a perspective view illustrating a modified form of a drivemechanism for the transport member.

FIG. 17 illustrates in partial schematic form the driving connection fordriving the infeed and outfeed conveyors when carried in a spiralconfiguration.

FIG. 18 is a perspective view illustrating the driving mechanism fordriving a conveyor belt of a modified configuration.

FIG. 19 is a plan view illustrating a modified form of the mainconveyor.

FIG. 20 is a plan view illustrating a modified form of the main conveyorand the mechanism for deflecting the articles off the main conveyor andfor receiving the articles back on the main conveyor.

FIG. 21 is a plan view illustrating in schematic form a modified form ofthe transport member.

FIG. 22 is a plan view illustrating in schematic form a modified form ofa transfer member forming part of the invention.

FIG. 23 is a partial schematic view of an alternate preferred drivemechanism arrangement for the infeed and outfeed conveyors.

FIG. 24 is a partial plan view of an alternative embodiment of thearticle transfer member according to the invention.

FIG. 25 is a perspective partial cutaway view of the embodiment of thearticle transfer member illustrated in FIG. 24.

FIG. 26 is a perspective view of the alignment rail mechanismillustrated in FIG. 24.

FIG. 27 is a alternative perspective view of the alignment railmechanism taken along the lines indicated in FIG. 26.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1, 2, 3 and 4 there is illustrated an apparatus forcontrolling the flow of articles 10 from an upstream delivery station(FIG. 4) to a downstream receiving station. The articles are beingcarried on a main conveyor 12 that is driven by any conventionalconveyor drive mechanism for transporting the articles 10 from theupstream delivery station. The articles are feed along the main feedconveyor 12 until they reach a deflecting rail 14 wherein they aredeflected off of the main conveyor 12 onto an infeed conveyor A. Theinfeed conveyor A is an endless conveyor and is driven by a variablespeed motor 16.

An outfeed conveyor B is carried on a support structure. Only thevertical posts 18 are being shown for purposes of clarity. A substantialportion of the run of the infeed and outfeed conveyors A and B areparallel to each other providing a space 20 therebetween.

A transport member D rides on a track carried by the support structurethat permits the transport member D to move backwards and forwards alongthe length of the infeed and outfeed conveyors A and B. The infeed drivemechanism 16 drives the infeed conveyor A in a first direction. Anoutfeed drive mechanism 22 drives the outfeed conveyor B in a seconddirection. A variable speed control 24 is operatively connected to theoutfeed drive mechanism for varying the speed of the outfeed conveyor.

A rotatable member E see FIGS. 10 and 11 is carried by the transportmember D. Drivers F are carried by the infeed conveyor A and engaged therotatable member E for rotating the rotatable member. Drivers G arecarried by the outfeed conveyor B and engage the rotatable member E forrotating the rotatable member and causing said transport member D tomove along a path parallel to the infeed conveyor A and the outfeedconveyor B, at a speed and direction depending on the relative speed ofthe infeed conveyor A and the outfeed conveyor B. An article transfermember H is carried by the transport member D for deflecting articlesfrom the infeed conveyor A to the outfeed conveyor B.

The speed of the outfeed conveyor is controlled by the variable speedmotor 22; and if the speed of the outfeed conveyor B is running slowerthan the speed of the infeed conveyor A then the transport member asshown in FIGS. 1, 2 and 3 is moved in the counter clockwise directionloading up the articles on the surfaces of the infeed conveyor and theoutfeed conveyor B for temporarily storing the articles in theaccumulator.

When the demand from the downstream receiving station increases, asignal is generated by condition responsive devices 32 and 34 positionedalong side of the conveyor B and on conveyor 12. These devices willcause the speed of the outfeed conveyor B to increase and be greaterthan the speed of the infeed conveyor. When this occurs, the transportmember D due to the driving connection between the infeed and outfeedconveyors A and B will move in a clockwise direction; and the number ofarticles stored on the infeed and outfeed conveyors A and B will bereduced and the first article that was stored is the first articledelivered from the outfeed conveyor B. The driving connection betweenthe transport member D and the infeed and outfeed conveyor A and B willbe discussed in greater detail below.

Condition responsive devices are positioned along the conveyors forgenerating signals responsive to various conditions. For example,condition responsive device 26 is positioned adjacent to the mainconveyor 12 for sensing a backup of articles on the main conveyor; andif such a condition occurs a signal is sent to a controller which causesthe infeed conveyor A to shift to a higher speed. The conditionresponsive device 26 may be any suitable conventional sensor, but in oneparticular embodiment it is a photocell provided with a timer so that ifthe photocell is activated for a certain period of time by non movementof the article a signal is generated. The articles 10 carried on themain conveyor are spaced apart, and as long as the space is sensedbetween the articles in a given period of time then no signal isgenerated by the photocell to trigger an increase in speed of the infeedconveyor A. One suitable photocell is manufactured by Sick A. G. havinga part number of WT4-2P135S10. Sick A. G. is located in Wldkirch,Germany. It is to be understood that any conventional suitableconditional responsive device could be used at any of the locationswhere one is required.

Another condition responsive device 28 is positioned along the mainconveyor closely adjacent to the front end of the rail 14. It isprovided to sense a backup on the conveyor, and causes a signal to beproduced to reduce the speed of the conveyor to a medium speed. Anotherconditional responsive device 30 is positioned near the entrance of theinfeed conveyor A for sensing a lack of products or articles on theinfeed conveyor A and this sensor stops the infeed conveyor when such acondition occurs.

There is still another condition responsive device 32, positionedadjacent to main conveyor 12, where the articles are fed back onto themain conveyor. When a backup of articles is sensed by conditionresponsive device 32 on the main conveyor 12, such stops the outfeedconveyor B. A backup is sensed when the articles exiting off of theoutfeed conveyor B are pressed against each other on the main conveyor12.

Under normal operation the main conveyor 12 is running at a higher speedthan the outfeed conveyor B, and as the articles are transferred fromthe outfeed conveyor B onto the main conveyor 12 a space is developedbetween the articles. The condition responsive device 32 is provided forensuring that this space remains between the articles, and if the spaceis lost as a result of a backup of articles then the outfeed conveyor Bis stopped. A still further condition responsive device 34 is positionedfurther down the line on the main conveyor, and when it senses thatthere is no space between the articles being delivered back onto themain conveyor a signal is generated, which is feed to the variable speedmotor 22 driving the outfeed conveyor B, for reducing the speed of thevariable speed motor 22. All of the signals generated by the conditionalresponsive devices are feed through conventional controllers such asprogrammable logic controller, which in turn is used for controlling thedrive speed of the infeed drive motor 16, and the outfeed drive motor22. One suitable programmable logical controller is manufactured byAllen Bradley and has a model number of SLC500 series. Allen Bradley islocated in Milwaukee, Wis.

In order for the transport member D to move from the position shown inFIG. 2 to the position shown in FIG. 1 the speed of the infeed conveyorA must be running faster than the speed of the outfeed conveyor B. As aresult, when the transport member D is moved in a counter clockwisedirection it is loading articles from the infeed conveyor A to theoutfeed conveyor B for storing the articles. As previously mentionedwhen the demand at the downstream receiving station increases then thespeed of the outfeed conveyor B will increase over the speed of theinfeed conveyor A; and due to the coupling provided between the infeedand outfeed conveyors and the transport member D, the transport member Dwill move in a clockwise direction from the position shown in FIG. 1 tothe position shown in FIG. 2 to unload the articles stored in theaccumulator.

The configuration for the parallel run of the infeed conveyor A and theoutfeed conveyor B can vary depending on the amount of floor space thatis desired to be utilized for the accumulator. In FIGS. 1 and 2 theconfiguration of the infeed and outfeed conveyors is in a spiral. InFIG. 3 the configuration of the infeed conveyor A and the outfeedconveyor B is also in a spiral but it has an elongated middle portion.If there is sufficient floor space the run of the two conveyors A and Bcan be in a horizontal plane.

As shown in FIG. 4 the configuration of the infeed conveyor A and theoutfeed conveyor B is in a vertical spiral so that a substantial amountof storage can be placed in a relatively small space. Sometimes as theheight of the spiral increases it is necessary to drive the infeed andoutfeed conveyors along the vertical path of the spiral so as tominimize the drag of the conveyors on the track. The drive mechanism isshown in schematic form in FIG. 4 and will be described in greaterdetail in connection with FIG. 13.

As can be seen in FIG. 4 the infeed conveyor A and the outfeed conveyorB are endless conveyors. The infeed conveyor A is driven by a motor 16,and its path extends upwards from adjacent the main conveyor 12 in aspiral configuration to pass over a drive sprocket 36 then down avertical run through an idle sprocket 38 and back to the track whichholds the conveyor in a vertical spiral. The track for holding theconveyor may be of any suitable construction and is supported onvertical posts 18 and cross bracing (not shown for purpose of clarity).The outfeed conveyor B is driven by the outfeed drive motor 22 by meansof a drive sprocket 40. The conveyor belt B passes around idle sprockets42 and 44 in its run.

The infeed conveyor A and the outfeed conveyor B may be constructed ofany suitable conventional chain belt that has connecting links, and inone particular embodiment has an upper surface such as shown in FIGS. 5and 6. The lower surface has driving lugs 46 provided thereon whichengage teeth provided on a sprocket carried by an output shaft of theinfeed drive motor 16. The outfeed conveyor B engages teeth carried on asprocket provided on an output shaft of the outfeed drive motor 22.

The driving links 46 have grooves provided so that the conveyor belts Aand B can ride on the track 58 and 60. The track is defined by twoelongated space strips 62 and 64 such as shown in FIG. 9. Drivers F inthe form of posts 48 are carried on the lower surface of each of thelinks 50 of the infeed conveyor A. Similar drivers G in the form ofposts 52 are provided on the lower surface of each of the links 54 ofthe outfeed conveyor B. The posts 48 and 52 extend downwardly from thelinks 50 and 54 respectively, for engaging teeth 61 provided in therotatable member E. As shown in FIG. 10 if the infeed conveyor A ismoving to the right at a higher rate of speed than the outfeed conveyorB is moving to the left the posts 48 and 52, engaging the teeth 61 ofthe rotatable member E will cause the rotatable member E to rotate andalso move to the right. For example the phantom line position drawntherein. If however, the outfeed conveyor B is moving to the left at afaster rate of speed than the infeed conveyor is moving to the right,then the rotatable member will be shifted to the left as it is rotated.

The rotatable member E is carried on a transport member D shown in anexploded view in FIG. 11. The transport member D includes a pair ofelongated plates 68 and 70. The plates are substantially rectangular inshape and have curved inner ends 72 and 74 respectively providedthereon. A post 76 projects upwardly from the inner end of the plate 70and extends through an opening 78 provided adjacent the inner end ofplate 68. An arcuately shaped rectangular guide bar 80 is carried on theupper surface of the plate 70 that fits within a groove 82 provided in alower surface of a dead plate 84. The dead plate is permitted to shiftlaterally slightly during the travel of the transport member aroundcurves.

A set of wheels 86 are carried on a horizontally extending bar 88carried adjacent to an outer end of the support plate 70. Thehorizontally extending bar 88 is pivotally attached to the support plateby a pivot pin 90. The wheels 86 are connected to upwardly extendingflanges 86 carried on the horizontal member 88 so as to permit them torotate freely thereon. A similar set of wheels 92 are carried on theouter ends of the plate 68 and are supported on vertically extendingflanges 94 connected to opposite ends of the horizontal bar 96. The bar96, in turn, is pivotally connected by means of a pivot post 98 to theplate 68. As a result, the wheels 86 and 92 can pivot about the pivotpoints 90 and 98 respectively, as the transport member moves around thecurves included in the spiral track.

In order to stabilize the pivotal movement of the wheels and assist themin following the curvature of the track, connecting linkages 102 and 104are pivotally connected to pivot posts 106 and 108, provided on thehorizontal bars 88 and 96. The linkage arms 102 and 104 have downwardlyextending posts 106 and 108 respectively, carried on the inner endsthereof, which project down within slots 110 and 112, provided in acircular plate 114. The circular plate is carried on the post 76. As aresult of the linkage arms 102 and 104 when the transport member goesaround a curved portion of the track, the wheels 86 and 92 follow thecurvature of the track. The linkage arm 102 and 104 control the movementof the sets of wheels 86 and 92.

As previously discussed the rotatable member E is carried on the post76, and has four circumferentially spaced, vertically extending pins116, provided on an upper surface thereof. These pins 116 are providedfor securing a guide wheel 118 on top of the rotatable member E. As aresult of the pins 116 extending through bores 120 provided in thewheel, the wheel 118 is rotated with the rotatable member E.

An article transfer member H is carried by the transport member D andhas a curvature similar to that of the curvature of a horseshoe. This isdefined by a pair of spaced end portions 122 and 124 which are joined byan arcuately shaped intermediate portion 126 (see FIG. 11). The endportions 122 and 124 extend over the infeed conveyor A and the outfeedconveyor B respectively, as shown in FIGS. 1 through 3. The guide plateis spaced from the rim of the wheel 118, so as to define a path throughwhich the articles 10 are guided as they are shifted from the infeedconveyor A to the outfeed conveyor B. Different sized and shaped wheels118 can be placed on the pins 116 for varying the size of the pathextending between the rim 119 of the wheel 118 and the inner surface ofthe guide plate H, and for transferring articles of different sizes andconfigurations.

In FIG. 7 the dead plate 130 over which the articles pass as they aremoved from the infeed conveyor A to the outfeed conveyor B is shown as aflat plate 130 that has an inner edge 132 which terminates adjacent theedge of the infeed conveyor A, and has an opposing edge 134 whichterminates closely adjacent the edge of the outfeed conveyor B. Theplate 130 is carried by the transport member D. In the embodiment shownin FIG. 11 the dead plate is allowed to move slightly in the lateraldirection on the rail 80.

Referring back to FIG. 7 there is shown how the plates 68 and 70 pivotabout the posts 76, as the transport member D moves around the curvesprovided in the guide track so as to follow the guide track accurately.The movement of the plates 68 and 70 is shown in phantom lines in FIG.7.

Referring to FIG. 8 of the drawings, the details of the track upon whichthe conveyor B is supported is illustrated. The track includes a pair ofspaced plates 58 and 60. The plates 58 and 60 are in turn supported on asuitable support structure that holds them in a fixed relation; and theplates 58 and 60 define the track which guides the conveyor in theconfiguration, such as the spiral configuration shown in FIG. 4. Theplate 58 has a bearing block 140 fixed on the inner end which is thereto provide a frictionless surface upon which the links of conveyor Brun. The plate 60 also has a “U” shaped bearing block 142 secured to theinner end thereof for supporting the links of conveyor B.

As can be seen, the links of the conveyor include a horizontallyextending upper surface 144, which have a pair of downwardly extendingspace flanges 146 and 148 extending from a lower surface thereof. Theseflanges 146 and 148 have inwardly extending horizontal flanges 150 and152 carried on a lower surface thereof, so as to define a groove intowhich the frictionless bearing blocks 140 and 148 ride when supportingthe links of conveyor B. The same linkage is provided on the infeedconveyor A as illustrated on the outfeed conveyor B in FIG. 8.

The tracks 58 and 60 are supported by any suitable cross framessupported on the vertically extending posts 18, and can be supported todefine any desired configuration for the infeed and outfeed conveyors Aand B, as shown in FIGS. 1-4.

In FIG. 16 there is illustrated a modified form of the invention, and inparticular the drive mechanism for the rotatable member E. The infeedconveyor A and the outfeed conveyor B have space slots 154 and 156provided in the surface thereof, into which the teeth of sprockets 158and 160 mesh. As a result, when the conveyors A and B are moving adriving rotational movement is imparted through the sprockets 158 and160 to a differential gear arrangement 162 for driving a chain 164. Thechain 164 is carried on a sprocket 166 which is secured to a shaft 168forming part of the differential gear arrangement 162. The chain 164extends around another sprocket 170 provided on the post 76 for rotatinga rotatable member F. A wheel 118 can be placed on top of the rotatingmember E shown in FIG. 16 in the same manner as illustrated in FIG. 11.The purpose of FIG. 16 is to show a modified drive mechanism forrotating the rotatable member E.

In FIG. 15 there is illustrated another modified form of the inventionwherein instead of using the arcuately shaped deflection plate H, suchas shown in FIGS. 11, an arcuately shaped movable belt is driven byposts 172 and 174 extending downwardly from the lower surface of theinfeed conveyor belt A and outfeed conveyor belt B. The post 172 and 174engage teeth 176 and 178 respectively carried on sprockets 180 and 182.The sprockets 180 and 182 are in turn rotatably supported on shafts 184and 186 that are carried on a lower service of the transport member. Amoveable belt 185 extends around the sprockets 180 and 182, and iscarried in a curved configuration defined by any suitable arrangement ofidle roles not shown. The belt 185 is driven by the infeed and outfeedconveyors A and B providing a moving surface for the articles beingtransferred from the infeed conveyor to the outfeed conveyor. Thedetails of the transport member are not illustrated in FIG. 15 forpurposes of clarity. The moving belt 185, in conjunction with the wheel118, transports the articles 10 from the infeed conveyor A to theoutfeed conveyor B, by providing two moving surfaces which engageopposite sides of the articles 10.

Referring now in more details to FIG. 13. Instead of the transportmember D having a dead plate 84 over which the articles 10 aretransported from the infeed conveyor A to the outfeed conveyor B, amoveable belt 190 is carried by the transport member D, and is supportedfor rotation on idle wheels 192 and 194. The moveable belt 190, hasposts 196 provided on a lower surface thereof, which engage the teeth 61of the rotatable member E. The belt 190 is driven by the rotatablemember E for aiding in transporting the articles 10 from the infeedconveyor A to the outfeed conveyor B.

Instead of using a single gear toothed rotatable member E, such as shownin FIG. 13, the drive mechanism for the wheel 118 that is carried on thetransport member can be a chain drive, such as illustrated in FIG. 14.In FIG. 14, two sprockets 198 and 200 are carried on a plate formingpart of the moveable member. A chain 202 extends around two drivensprockets 201 and 203, which are rotated by the shafts 205 and 207 thatthe sprockets 198 and 200 are fixed to. The sprockets 198 and 200 arerotated as the sprockets engage the posts 48 and 52 carried on the lowersurface of the infeed and outfeed conveyors A and B respectively. Thechain 202 extends around a sprocket 204 that in turn is rotated aroundposts 206. The chain 202 and sprocket arrangement shown in FIG. 4performs the same function as the rotatable gear E shown in FIG. 11. Theremaining structure, such as the rotatable wheel 118 and guide plate H,could be the same as the structure included in the transport member D ofFIG. 11.

When the configuration of the infeed and outfeed conveyors A and Bextends vertically upwardly in several layers, such as shown in FIG. 4,it is desirable that each layer of the conveyor is driven from theinfeed drive motor 16 and the outfeed drive motor 22. This overcomes thedrag produced by the long run of the conveyor chains A and B. In FIG.17, there is illustrated a drive mechanism for such a spiralconfiguration . The various layers of the infeed and outfeed conveys Aand B are shown stacked one upon the other in FIGS. 4 and 17. The infeedmotor 16 is connected through a gear box 210 which has output driveshafts 212 and 214 extending outwardly therefore. The output drive shaft212 is connected to a gear box 216 which is connected to a verticallyextending shaft 218. The vertically extending shaft 218 has gear boxes220, 222 and 224 spaced therealong, so that there is a drive connectionfrom the motor 16 to each of the gear boxes 220, 222 and 224. Each ofthe gear boxes 220, 222 and 224 have an output shaft 226 which drives adriving gear 228 that is a driving engagement with the infeed conveyorA. An idle gear 230 is provided on the outer end of the shafts 226 thatengage the outfeed conveyor B. The output shaft 214 of the gearbox 210is connected to a gear box 236 which in turn drives a verticallyextending shaft 238. The vertically extending shaft 238 has gear boxes240, 242 and 244 spaced vertically therealong. Gear boxes 240, 242 and244 have output shafts 246, 248 and 250 respectively. Each of theseshafts, 246, 248 and 250 have driving gears 252 provided thereon, whichengage the lugs of the infeed conveyor A for driving the various layersof the infeed conveyor A. Idle gears 254 are carried on the end of theshafts 246, 248 and 250 for engaging the outfeed conveyor B.

The outfeed conveyor B is driven by the variable speed motor 22 througha gear box 256. The gear box 256 in turn is used for driving verticallyextending shafts 258 and 260. The vertically extending shafts 258 and260 have gear boxes 262 provided along the length thereof. Each of thegear boxes 262 have an output shaft 264 extending therefrom for drivinga sprocket 266 which engages the outfeed conveyor B. An idle sprocket268 engages the infeed conveyor A. Chains 270 and 272 extend between thedriven sprocket 266 and the idle sprocket 230 such as shown on the topleft, and the driven sprocket 228 as well as the idle sprocket 268. Thechains extending around a driven sprocket and an idle sprocket aids, instabilizing the driving force imparted to the conveyor belts A and B.

The condition responsive devices 26, 28, 30, 32 and 34 (FIG. 1) sensethe various flow of articles on the conveyors, such as described abovein connection with FIG. 1, and send signals to a PLC which is used forvarying the speed of the outfeed motor 22. As previously mentioned, thespeed of the main conveyor 12 can be stopped. Also, the speed of theinfeed conveyor A and outfeed conveyor B can be stopped depending on theflow of articles through the accumulator as described previously.

In FIGS. 19 and 20 there are illustrated two different arrangements forthe main conveyor 12 which transports the articles 10 from the upstreamstation to the downstream station. In the embodiment illustrated in FIG.19, the main conveyor includes two conveyors 12 a and 12 b. The articlesbeing transported on the main conveyor 12 a are deflected onto theinfeed conveyor A by means of an angled deflecting rail 300. Thearticles coming off the outfeed conveyor B are guided onto the mainconveyor 12 b by the spaced guide rails 302 and 304.

In FIG. 20 instead of using two main conveyors 12 a and 12 b a singlemain conveyor 12 is utilized. When it is desired to deflect the articlesfrom the main conveyor 12 to the infeed conveyor A, a deflecting guiderail 306 is moved by a pneumatic or hydraulic cylinder 308 from the fullline position to the phantom line position. When the guide rail is movedto the full line position the accumulating function is taken out ofservice, and the articles are moved directly along the main conveyor. Asimilar deflecting plate 310 is associated with the outfeed conveyor B,and when it is desired that the articles be allowed to flow directlyfrom the upstream delivery station to the downstream receiving stationwithout going through the accumulator, the deflecting plate 310 is movedto the full line position. However, when the accumulator is in use, thedeflecting plate is moved to the phantom line position by means of apneumatic or hydraulic cylinder 312.

SUMMARY OF THE OPERATION

Attention is directed to FIG. 2 of the drawings. As can be seen in FIG.2, articles 10 are feed on the main conveyor 12 onto an infeed conveyorA which is an endless conveyor belt. The articles are then moved on theinfeed conveyor A up and around the infeed conveyor A until they engagea deflecting plate H carried on a transport member D. The deflectingplate H deflects the articles over the movable transport member D fromout the infeed conveyor A to the outfeed conveyer B. If the speed of theoutfeed conveyor B is the same as the speed of the infeed conveyor A,then the articles merely moved over the dead plate 84 of the transportmember D to the outfeed conveyor B, and are fed back onto the mainconveyor 12. However, if for example there is no demand for articlesfrom the downstream receiving station, and as a result the outfeedconveyor is stopped, the transport member D will move in a counterclockwise direction around the spiral causing the articles being feed inon the infeed conveyor A to be lined up on the outfeed conveyor B. Thisaction continues until the transport member D reaches the top of thespiral, wherein it engages a limit switch that stops the entireaccumulation system.

If, however, prior to reaching the top of the spiral the downstreamreceiving station begins taking articles from the main conveyor 12 asignal is generated, by the condition responsive devices 32 and 34,turning on the motor 22 driving the outfeed conveyor B. The outfeedconveyor B begins running faster than the infeed conveyor A, and as aresult, the articles are transferred in sequence from the outfeedconveyor B back onto the main conveyor 12. The incoming articles 10 thatare being feed on the infeed conveyor A are continuously loaded on theoutfeed conveyor but, as a result of the transport member moving in aclockwise direction, the number of articles in the accumulator decreasesuntil the accumulator is entirely empty. When the transport memberreaches the bottom of the spiral it engages another limit switch whichstops the transport member from any further movement.

The movement of the transport member D is controlled by the speed of theinfeed and outfeed conveyors A and B. Referring now to FIG. 10, theinfeed conveyor A and the outfeed conveyor B have posts 48 and 52provided thereon which engage the teeth of a rotatable member E. If thespeed of the infeed conveyor A is the same as the speed of the outfeedconveyor B then the transport member D, which carries a rotatable memberE, remains in the same position. However, if the outfeed conveyor Bslows down relative to the infeed conveyor, the moveable member will bemoved to the right as illustrated in FIG. 10, and the articles areloaded along the outfeed conveyor B until the speed of the outfeedconveyor B is increased to deliver more articles to the downstreamreceiving station.

When the speed of the outfeed conveyor increases above the infeedconveyor A, such causes the transport member to rotate rotatable memberE to move to the left and unload the accumulator.

One advantage of this accumulator is that the first article in is thefirst article out (FIFO), and as a result the sequence from which thearticles are fed from the upstream delivery station is alwaysmaintained.

When the articles are fed from the upstream delivery station there isnormally a space between the articles. The speed of the infeed conveyorA is slower than the speed of the main conveyor 12, and as a result whenthe articles 10 are transferred from the main conveyor 12 onto theinfeed conveyor A, they are positioned close to each other with verylittle space therebetween. When the articles 10 return to the mainconveyor 12 from the outfeed conveyor a space is produced between thearticles.

Since the articles do not move relative to the surface of the conveyorsA and B, there is very little rubbing between the articles as they arebeing stored and removed from the accumulator. This minimizes any damageor scraping of the labels carried on the articles.

The condition responsive devices 26, 28, 30, 32 and 34 control the speedof the conveyors through a programmable logic controller. If, forexample, the downstream receiving station stops receiving articles 10,the articles 10 will back up on the main conveyor 12 and the photocell34 senses such backup and sends a signal to the PLC to reduce the speedof the outfeed conveyor B. If the backup of the articles extends to thecondition responsive device 32 as a result of the lost spacing betweenthe articles, then the condition responsive device 32 generates a signalthat is fed to the PLC which stops outfeed conveyor B. This causes thearticles to be loaded into the accumulator from the bottom of the spiralto the top.

If prior to the transport member D reaching the top of the spiral asignal is received indicating that the downstream receiving station canreceive more articles, the PLC under the control of the conditionresponsive devices 32 and 34 send a signal to the outfeed motor 22increasing the speed of the outfeed conveyor B above the speed of theinfeed conveyor A. When this occurs the articles that have been storedin the accumulator are fed by the outfeed conveyor B back onto the mainconveyor to the downstream receiving station. Since the articles thatare being fed into the accumulator on the infeed conveyor A is at aslower rate than they are being removed from the accumulator by theoutfeed conveyor, such causes the transport member to move in aclockwise direction until the accumulator is entirely emptied.

Referring now to FIG. 21 of the drawing, there is illustrated a modifiedform of the invention. The rotatable member E, which is driven by theinfeed and outfeed conveyors A and B, has provided on top thereof a thinflat large diameter metal plate 350 (conveying plate) that extends overthe upper surface of the infeed conveyor A and outfeed conveyor B fortransferring articles 10, being transported on the infeed conveyor A tothe outfeed conveyor B. The articles being moved on the infeed conveyorA ride up on the upper surface of the thin metal plate 350, and as themetal plate 350 is rotated by the rotatable member E, it transports thearticles 10 over the upper surface of the outfeed conveyor B. Adeflecting rail 352 is used for deflecting the articles from the uppersurface of the flat plate 350 on to the conveyor B.

Still another modified form of the invention is disclosed in FIG. 22,wherein griping arms 354, projecting outwardly from a rotatable housing360, are used for gripping the articles 10 moving on the infeed conveyorA and transferring the articles to the outfeed conveyor B. The grippers354 can be any suitable gripping jaws that are closed by a cam or anyother suitable mechanism as the gripping jaws pass over the infeedconveyor A for gripping the articles 10 and transporting them over tothe outfeed conveyor B where they are released. The housing 360 can bedriven by the rotatable member described in the earlier embodiments.

While the drivers F and G between the rotatable member E and the infeedconveyor A and outfeed conveyor B has been shown in one particularembodiment as being post 48 and 52 provided on the lower surface of aconveyor meshing with teeth 61 provided on the rotatable member E, it isto be understood that such driving connection between the infeed andoutfeed conveyors A and B, and the rotatable members could beaccomplished by other means such as, for example, placing sockets orteeth on the conveyor belts A and B and mounting the posts on therotatable member E.

In FIG. 18 there is illustrated a different type of conveyor belt thatcould be utilized with the invention. The conveyor belt includes links300 which are joined together along the length of the conveyor as wellas across the conveyor. This is a conventional link belt type ofconveyor chain. Posts 302 are mounted to the lower ends of the linkscarried on the outside of the chain for driving the rotatable member Esuch as shown in FIG. 10. The conveyor chain has openings 304 providedtherein into which teeth 306 carried on sprockets extend for producing adriving relation between the sprockets. The primary purpose of includingthe chain of FIG. 18 is to illustrate that any suitable conventionalconveyor belt can be modified to be utilized as part of the accumulator.

ADDITIONAL DESCRIPTION

An alternative preferred drive mechanism arrangement for the infeed andoutfeed conveyors is illustrated in the partial schematic perspective ofFIG. 23. According to this embodiment, a plurality, for example three orfour, individual drive mechanisms 22 a through 22 c and 16 a through 16c are provided for the outfeed and infeed conveyors B and A,respectively. Each drive mechanism includes a motor driving a gearingarrangement and drive sprocket 102. A chain 104 is driven by drivesprocket 102 and passes around an idler sprocket 103. Although notillustrated in FIG. 23, chain 104 includes driving engagement members orlugs that engage with the drive lugs on the bottom of the conveyors.This type of drive motor arrangement is but one type of preferredmechanism, and it should be understood that any manner of conventionaldrive mechanism may be utilized in this regard. A suitable preferreddrive mechanism is described in detail in co-pending U.S. patentapplication Ser. No. 09/235,887, now U.S. Pat. No. 6,119,848 filedconcurrently with this application on Jan. 22, 1999 and entitled“Conveyor Motor Drive Unit and Conveyor System”. The No. 09/235,887application is incorporated herein by reference for all purposes.

Applicants have found that the use of individual drive motors ormechanisms spaced along the conveyors provides a significant benefit.Each of the motors is individually driven and powered and is independentof the other motor drive mechanisms. Each motor drive has an inherentload-torque curve wherein the motor will increase or decrease in speedaccording to the load carried by the motor, as is commonly understood.In this regard, referring to FIG. 23 and outfeed conveyor B as anexample, when outfeed conveyor B passes over motor drive unit 22 a, thelinks of outfeed conveyor b are compressed or drawn together due to thedriving action of the motor resulting in a degree of “slack” generatedin the conveyor. This “slack” would tend to bunch together the articlescarried on the conveyor and if the articles are already in contactingrelation, the articles may be forced off of the conveyor. The use ofmultiple independent drive mechanisms substantially eliminates thisoccurrence. For example, any slack generated by drive mechanism 22 a isimmediately sensed as a decrease in load at drive mechanism 22 b causingdrive mechanism 22 b to increase slightly in speed thus taking up anyslack generated in the conveyor. Likewise, drive mechanism 22 c willrespond similarly to any slack generated by drive mechanism 22 b. Thus,as a result of the ability of the individual drive mechanisms to operateindependently along their respective load-torque curves, the problem ofslacking and bunching on the conveyors is eliminated.

The same discussion relating to drive mechanisms 22 a through 22 c alsorelates to drive mechanisms 16 a through 16 c and their relationshipwith infeed conveyor A.

In the embodiment wherein infeed and outfeed conveyors A and B are in astacked spiral arrangement, the individual drive mechanisms are providedat each layer of the stacked arrangement.

Each of the individual drive mechanisms is connected via control lines105 to a PLC cabinet 100 or other suitable control system. Each of theindividual drive mechanisms is preferably supplied with the same voltageand frequency power supply. Control system or PLC 100 may beincorporated with the same PLC or control system utilized forcontrolling the speeds of the conveyors in response to the conditionedresponsive devices 26, 28, 30, 32, 34, as described above.

FIGS. 24 and 25 illustrate an alternative preferred embodiment ofarticle transfer member H. This embodiment is similar in aspects to thatillustrated and described with regards to FIG. 21. In this embodiment,rotatable member E is rotatably driven by engagement with the driversprovided on the underside of the infeed and outfeed conveyors A, B. Aring gear 138 is fixed to the upper surface of rotatable member E and isnon-rotatable relative thereto. A sun gear 142 is disposed concentricwith the central axle 144 of rotatable member E. A plurality of planetgears 140, for example four, are disposed between sun gear 142 and ringgear 138. Each of the planet gears includes an upstanding axle 146. Asis conventionally understood, as the ring gear rotates with rotatablemember E, planet gears 138 will revolve relative to sun gear 142 andcental axle 144. A conveying plate 106 that comprises an essentiallyflat thin plate is engaged on each of the planet gear axles 146.Accordingly, conveying plate 106 will rotate at the same speed thatplanet gears 140 revolve around sun gear 142. This gear reductionmechanism is utilized so that conveying plate 106 does not rotate at thesame speed as rotatable member E. By reducing the rotational speed ofplate 106, articles carried thereon are not thrown, moved, or bumped offof the plate, and do not jam as they are carried onto and off ofconveying plate 106.

Conveying plate 106 can comprise any conventional material, for example,a simple metal plate. It may be preferred to coat plate 106 with anymanner of conventional coating to, for example, decrease the tendency ofthe articles to slide or move on the plate surface.

FIG. 25 also illustrates a deflecting rail mechanism 108 that may beincorporated as a preferred feature of the invention. Rail mechanism 108includes a relatively rigid rail member 110 resiliently mounted ontransport member D. For example, rail 110 may be mounted on a framemember 114 carried by transport member D. The deflecting rail mechanism108 includes a number of resilient fingers 112 also mounted on framemember 114. Fingers 112 may be formed of any resilient material, forexample a thin flexible metal, plastic, rubber, or the like. Fingers 112tend to press rail 110 outward into outfeed conveyor B, as indicated indashed lines in FIG. 25. The front end of rail 110 is rigidly mountedonto a plate member 118 that fits over central axis 144 of rotatablemember E. In this regard, the resiliency of rail 110 tends to increasefrom the front or forward end as the rail extends rearward. In otherwords, rail 110 is less resilient where the rail is mounted onto plate118 but becomes more resilient by way of fingers 112 as the articles aretransferred off of conveying plate 106 and onto outfeed conveyor B. Inthis way, rail 110 applies a constant bearing pressure against thearticles as they are transferred onto outfeed conveyor B.

FIGS. 26 and 27 illustrate an alternate preferred feature that may beincorporated with the present invention, particularly an alignment railmechanism, generally 120. Alignment rail mechanism 120 is also carriedby transport member D and is located adjacent to rotatable member E andconveying plate 106 so as to align and position articles for transferfrom infeed conveyor A to outfeed conveyor B. Alignment rail mechanism120 preferably includes a relatively rigid rail 122 that is movabletowards and away from infeed conveyor A, as generally indicated by thedashed lines in FIG. 25. Rail 122 is mounted onto a frame member 124 byway of arms 125 that are pivotably mounted to frame 124. An arm 128extends from arms 125 and carries a weight 126. Weight 126 is variablypositionable along arm 128 to vary the amount of movement, and thuspressure, exerted by rail 122 against articles conveyed on infeedconveyor A.

Rail 122 may also include a flexible or resilient arm section 130,generally illustrated in FIG. 27. Resilient arm section 130 may beattached to rail 122 in any conventional manner, such as the pinarrangement 132 illustrated in FIG. 27. Pins 132 allow for variablepositioning and adjusting of resilient arm section 130 depending on theamount and type of articles being conveyed.

It should be appreciated that the alignment rail member can beconfigured in a number of alternate ways. For example, FIG. 27illustrates rail 122 as mounted on a member 127 that is rigidly fixed toswinging arms 125. Any type of structure may be utilized to mount rail122 and to provide a variable force or positioning capability for therail.

As described above, infeed and outfeed conveyors A, B may be constructedof any suitable conventional chain belt that has connecting links. Thelower surface has driving lugs provided thereon which are engaged by thebelt drive mechanism. Driver engagement members are also disposed on thebottom of the conveyors for engaging rotatable member E, as discussedabove. Applicants have found that a preferred embodiment of conveyorbelts A and B is the type of belt described and illustrated in pendingU.S. Provisional patent application Ser. No. 60/107,171 filed on Nov. 5,1998 and entitled “Conveyor Belt and Modules with Tapered Oblong HingePins”. The '171 Provisional application is incorporated herein byreference for all purposes.

While preferred embodiments of the invention have been described above,it is to be understood that any and all equivalent realizations of thepresent invention are included within the scope and spirit thereof.Thus, the embodiments depicted are presented by way of example only andare not intended as limitations upon the present invention. Whileparticular embodiments of the invention have been described and shown,it will be understood by those of ordinary skill in this art that thepresent invention is not limited thereto since many modifications can bemade. Therefore, it is contemplated that any and all such embodimentsare included in the present invention as may fall within the literal orequivalent scope of the appended claims.

What is claimed is:
 1. An apparatus for controlling the flow ofarticles, comprising: an infeed conveyor driven in a first direction toconvey articles therealong in said first direction, and an outfeedconveyor driven in an opposite direction to convey articles therealongin said opposite direction; said infeed and outfeed conveyors spacedapart and generally parallel so as to define a space therebetween; amoveable transport member disposed generally across and moveable alongsaid space, said transport member further comprising a unitary rotatablemember drivingly engaged on a common single circumferential drivesurface simultaneously by said infeed and outfeed conveyors so that saidrotatable member continuously rotates as either of said infeed andoutfeed conveyors move and said transport member travels along saidspace if a relative speed difference exists between said infeed andoutfeed conveyors causing said transport member to travel in thedirection of the faster of said infeed and outfeed conveyor; and aarticle transfer member carried by said transport member and operablydisposed between said infeed and outfeed conveyors to transfer articlesbetween said infeed conveyor and said outfeed conveyor as said rotatablemember rotates relative to said infeed and outfeed conveyors.
 2. Anapparatus for controlling the flow of articles, comprising: and infeedconveyor driven in a first direction to convey articles therealong insaid first direction, and an outfeed conveyor driven in an oppositedirection to convey articles therealong in said opposite direction; saidinfeed and outfeed conveyors spaced apart and generally parallel so asto define a space therebetween; a moveable transport member disposedgenerally across and moveable along said space, said transport memberfurther comprising a unitary rotatable member drivingly engaged on acommon drive surface simultaneously by said infeed and outfeed conveyorsso that said rotatable member continuously rotates as either of saidinfeed and outfeed conveyors move and said transport member travelsalong said space if a relative speed difference exists between saidinfeed and outfeed conveyors causing said transport member to travel inthe direction of the faster of said infeed and outfeed conveyor; aarticle transfer member carried by said transport member and operablydisposed between said infeed and outfeed conveyors to transfer articlesbetween said infeed conveyor and said outfeed conveyor as said rotatablemember rotates relative to said infeed and outfeed conveyors; andwherein said article transfer member comprises an arcuately shapeddeflector plate having one end extending over said infeed conveyor andanother end extending over said outfeed conveyor for deflecting articlesfrom said infeed conveyor to said outfeed conveyor.
 3. The apparatus asin claim 2, wherein said article transfer member further comprises arotatable wheel mounted on said transport member, said wheel having arim spaced from and defining a path with said arcuately shaped deflectorplate through which articles are deflected from said infeed conveyor tosaid outfeed conveyor.
 4. An apparatus for controlling the flow ofarticles, comprising; an infeed conveyor driven in a first direction toconvey articles therealong in said first direction, and an outfeedconveyor driven in an opposite direction to convey articles therealongin said opposite direction; said infeed and outfeed conveyors spacedapart and generally parallel so as to define a space therebetween; amoveable transport member disposed generally across and moveable alongsaid space, said transport member further comprising a unitary rotatablemember drivingly engaged on a common drive surface simultaneously bysaid infeed and outfeed conveyors so that said rotatable membercontinuously rotates as either of said infeed and outfeed conveyors moveand said transport member travels along said space if a relative speeddifference exists between said infeed an outfeed conveyors causing saidtransport member to travel in the direction of the faster of said infeedand outfeed conveyor; a article transfer member carried by saidtransport member and operably disposed between said infeed and outfeedconveyors to transfer articles between said infeed conveyor and saidoutfeed conveyor as said rotatable member rotates relative to saidinfeed and outfeed conveyors; and wherein said infeed and outfeedconveyors comprise spaced apart drive lugs that drivingly engage withcorrespondingly sized sockets defined around a circumference of saidrotatable member.
 5. The apparatus as in claim 1, further comprising atleast one drive mechanism configured with each of said infeed andoutfeed conveyors to move said conveyors in their respective directions.6. An apparatus for controlling the flow of articles, comprising; aninfeed conveyor driven in a first direction to convey articlestherealong in said first direction, and an outfeed conveyor driven in anopposite direction to convey articles therealong in said oppositedirection; said infeed and outfeed conveyors spaced apart and generallyparallel so as to define a space therebetween; a moveable transportmember disposed generally across and moveable along said space, saidtransport member further comprising a unitary rotatable member drivinglyengaged on a common drive surface simultaneously by said infeed andoutfeed conveyors so that said rotatable member continuously rotates aseither of said infeed and outfeed conveyors move and said transportmember travels along said space if a relative speed difference existsbetween said infeed and outfeed conveyors causing said transport memberto travel in the direction of the faster of said infeed and outfeedconveyor; a article transfer member carried by said transport member andoperably disposed between said infeed and outfeed conveyors to transferarticles between said infeed conveyor and said outfeed conveyor as saidrotatable member rotates relative to said infeed and outfeed conveyors;at least one drive mechanism configured with each of said infeed andoutfeed conveyors to move said conveyors in their respective directions;and further comprising a plurality of independent drive motorsconfigured spaced apart along each of said infeed and outfeed conveyors,each of said drive motors having a load-torque curve such that saidmotors will increase in speed to take up any slack in said conveyors sothat articles on said conveyors are prevented from bunching on saidconveyors.
 7. The apparatus as in claim 6, wherein said motors arecontrolled from a common controller.
 8. The apparatus as in claim 6,wherein at least said motors configured with said outfeed conveyor areadjustable variable speed motors controlled from a common controller. 9.The apparatus as in claim 6, wherein said infeed and outfeed conveyorsare supported on a support structure such that a substantial portion ofsaid infeed and outfeed conveyors are in a vertically extending spiral,wherein at least one drive motor is provided for each of said conveyorsat each spiral layer.
 10. The apparatus as in claim 9, wherein saidinfeed and outfeed conveyors are endless conveyors.